Gmail is an email service that allows users to send and receive emails [3]. A user attempted to send an email to a recipient with a Gmail address, but the email was rejected by the server because the recipient's email account did not exist [3]. Users can access their Gmail accounts on their iPhones and use the Google Calendar app to manage their calendars [1] [4]. The Google Calendar app can be used to create and manage events, and events can be automatically created from emails received in Gmail [4]. Gmail users can also set up out-of-office notifications [5]. Gmail has a feature to merge accounts with iCloud, and users can switch their calendar settings to on or off [1] [6].